1. Field of the Invention
The present invention generally relates to an automobile door window assembly and, more particularly, to a windowpane guide structure for guiding a windowpane between closed and open positions.
2. Description of the Prior Art
Japanese Laid-open Utility Model Publication No. 60-137616, published Sept. 12, 1985, discloses a automobile door assembly of a type reproduced in FIG. 1 of the accompanying drawings. The prior art door assembly shown in FIG. 1 comprises a door 1 having a sandwich structure comprising inner and outer door panels defining a windowpane chamber therebetween, and a door windowpane 4 supported for movement between an upwardy shifted, closed position, in which the windowpane is exposed to the outside of the windowpane chamber, and a downwardly shifted, open position in which the door windowpane is generally completely concealed within the windowpane chamber.
A windownpane guide structure employed in the prior art door assembly is housed completely within the windowpane chamber between the outer and inner door panels forming the door 1 and comprises front and rear channel members 2 and 3 secured to either the outer door panel or the inner door panel and spaced apart from each other in the lengthwise direction of the automobile. While the front and rear channel members 2 and 3 are open towards the door windowpane 4, front and rear brackets 5 and 6 each having a plurality of slide or roller members carried thereby are secured to lower front and rear edge portions of the door windowpane 4, respectively, with the slide or roller members movably engaged in the associated channel members 2 and 3. Although not shown, the door windowpane 4 can be moved between the open and closed positions by means of either a cranking knob or a powered window regulator.
However, for maximizing the capacity of the passenger's compartment within the limited framework of an automobile to provide a comfortable ride and to contribute to a configuration of the body will appeal to potential users, some automobiles make use of a windowpane, for each door asssembly, which is curved to protrude outwardly of the passenger's compartment when the windowpane is in the closed position. According to the prior art windowpane guide structure utilizing the curved windowpane, guide rails are provided along which the windowpane is moved with its opposite side edges slidingly engaged therein either directly or through guide rollers. These guide rails are nevertheless curved to conform to the curvature of the windowpane and are fixed to one of the inner and outer door panels.
When the windowpane has a relative large degree of curvature, for a given spacing between the outer and inner door panels forming the door assembly, an upper portion of the windowpane may be left exposed outwardly of the windowpane chamber even when the door windowpane is completely moved to the open position. This is because, when the door assembly is closed an associated side still extends immediately below the door assembly in a direction longitudinally of the automobile body structure and, the outer and inner door panels are, at the bottom of the door assembly, connected together by means of a bottom trim panel secured at its opposite side edges to the bottom edges of the outer and inner door panels while extending generally diagonally upwardly from the bottom edge of the outer door panel to the bottom edge of the inner door panel so as to compliment the contour of such side still. This is also because the open position for the movement of the door windowpane is delimited at so relatively high a level above the boot floor of the automobile as to avoid any possible collision of the lowermost edge of the door windowpane against the bottom trim panel when the windowpane is moved completely to the open position.
If the space between the outer and inner door panels is large, that is if the door assembly has a relatively thickness great enough to accommodate the curvature of the windowpane, the above-discussed problems might not be encountered; however, this is not a favorable solution in terms of the layout of the automobile bodywork and interior.